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建立了一种同时测定无糖食品中多种糖醇类甜味剂的气相色谱定量分析方法。样品中的糖醇经水提取,净化、脱水后,在吡啶-乙酸酐(1∶1,V/V)存在条件下,于90℃反应20 min,生成的糖醇乙酸酯衍生物用OV-101毛细管色谱柱(50 m×0.25 mm×0.33μm)分离,氢火焰离子化检测器(FID)进行测定及气相色谱-质谱结构鉴定。在优化的色谱分析条件下,实现了赤藓糖醇、木糖醇、甘露糖醇、山梨糖醇和麦芽糖醇衍生物的理想分离,并排除了常见糖类对糖醇测定的干扰。本方法在0.01~1.6 mg/mL范围内,对糖醇浓度与其衍生物峰面积进行线性回归分析,其相关系数在0.9995~0.9999之间。平均回收率为74.6%~113.4%,相对标准偏差在2.4%~8.6%之间。本方法操作简便、快速、可靠,检测限和加标回收率均能满足无糖食品中糖醇的定量分析要求。 相似文献
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1 引 言淀粉糖浆是由淀粉经水解、脱色和浓缩制成的 ,主要应用于食品工业。传统的分析方法是采用化学法测定其中总糖和还原糖的含量。由于采用化学法时 ,样品具有颜色或具有其它还原性物质时 ,对分析结果的准确性影响很大 ,而且 ,化学法不能测定出糖浆中各种糖的含量。本文采用二甲基亚砜为溶剂 ,环己烷为萃取剂 ,六甲基二硅氨烷和三甲基氯硅烷为衍生化试剂 ,对样品直接进行衍生化 萃取处理 ,用毛细管气相色谱法测定了淀粉糖浆中的糖含量 ,方法的相对标准偏差小于 4%。2 实验部分2 .1 仪器与试剂 GC1 2 2气相色谱仪 (上海分析仪器… 相似文献
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利用离子色谱法同时测定烟草中鼠李糖、葡萄糖、木糖、果糖、蔗糖和麦芽糖。采用超声浸提烟草中的糖,经Metrosep Carb 1阴离子交换柱分离,以0.100mol·L-1氢氧化钠溶液为淋洗液,采用脉冲安培检测器检测。6种糖的浓度在一定范围内与峰面积呈线性关系,方法的检出限在0.012~0.055mg·L-1之间。样品回收率在92.6%~105%之间,测定值的相对标准偏差(n=6)在0.6%~2.0%之间。方法用于快速分析烤烟的上、中、下部中6种糖的含量。 相似文献
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高效液相色谱法测定烟草中水溶性糖 总被引:1,自引:0,他引:1
提出了高效液相色谱法测定烟草中水溶性糖含量的方法。烟草样品经0.01mol·L~(-1)氢氧化钠溶液振荡提取60 min,以Metacarb 67C色谱柱(300mm×6.5mm)为固定相,纯水为流动相等梯度洗脱,用示差折光检测器检测。烟草中主要的水溶性糖均在12 min内达到基线分离,果糖、葡糖糖和蔗糖的检出限(3S/N)分别为0.60,0.71,0.39 mg·L~(-1)。方法加标回收率在98.1%~99.2%之间,相对标准偏差(n=8)在0.97%~1.6%之间。 相似文献
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采用苯酚-硫酸比色法测定明日叶水溶性总糖含量.以葡萄糖为标准品,6%苯酚溶液和浓硫酸作显色剂,应用分光光度法在490 mn波长处测定样品的吸光度,按标准曲线计算总糖含量.实验结果表明,明日叶水溶性总糖提取物中总糖含量(质量分数)为17.82%,实验精密度及重复性好.高、中、低三种不同浓度加样量加标回收率分别为101.55%、100.42%、101.26%,相对标准偏差(RSD)分别为:1.67%、0.76%、1.38%,回收率高.此方法操作简便,重复性、稳定性好,准确度高,可为明日叶水溶性总糖含量测定提供可靠的定量检测方法,为明日叶进一步研究开发提供科学依据. 相似文献
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H. Tang G. Richards K. Gunther J. Crawford M. L. Lee E. A. Lewis D. J. Eatough 《Journal of separation science》1988,11(11):775-782
A combined sampling and analysis technique for the determination of gas phase nicotine and 3-ethenylpyridine, and of particulate phase nicotine in environmental tobacco smoke with capillary gas chromatography is reported. The major advantage of the technique is that all of the collected particulate phase material is analyzed by thermal desorption of the collected material rather than by analysis of only a fraction of the sample extracted from the collection medium. A Teflon filter microtube is used to collect particulate phase nicotine. This microtube is follwed by a small Tenax sorbent bed to collect gas phase nicotine and 3-ethenylpyridine. After sampling, the Teflon filter is transferred to a clean glass tube and the tube becomes an insert for a modified packed column injector port where the material collected on the filter is heat desorbed to a cold capillary tubing trap. Gas phase nicotine and 3-ethenylpyridine are also transferred from the Tenax to the GC column by thermal desorption from the Tenax sorbent bed. Gas phase nicotine and 3-ethenylpyridine, and particulate phase nicotine are each determined by GC analysis of the desorbed material. Nicotine and 3-ethenylpyridine are quantitated by the use of external standards. This technique is straightforward and can be used for semi-real time determination of both gas and particulate phase compounds in environmental tobacco smoke. The results obtained by this technique compare well with those obtained by sampling with annular diffusion denuders. 相似文献
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Summary A reversed-phase liquid chromatographic method with sodium dodecylsulphate-n-propanolwater as mobile phase has been used to separate and determine six water-soluble vitamins in twelve minutes. The analytical
characteristics linear range, sensitivity, detection limits, and precision were evaluated. The lowest detection limits were
those of nicotinic acid (not usually present in pharmaceutical products), 0.7 mgL−1, nicotinamide, 1.3 mg L−1, and pyridoxine, 1.4 mg L−1. When the method was applied to the determination of the vitamins in pharmaceutical samples the values found agreed with
those on the labels. 相似文献
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Analysis of pesticide residues in tobacco with online size exclusion chromatography with gas chromatography and tandem mass spectrometry 下载免费PDF全文
Weiyun Guo Zhaoyang Bian Gangling Tang Deguo Wang Guanghui Li Jianlong Wang 《Journal of separation science》2016,39(14):2754-2759
An ultrasensitive method for the simultaneous analysis of pesticides residues in tobacco was developed with online size exclusion chromatography with gas chromatography and tandem mass spectrometry. Tobacco samples were extracted with the solvent mixture of cyclohexane and acetone (7:3, v/v) and centrifuged. Then, the supernatant liquors were injected directly into the online size exclusion chromatography with gas chromatography and tandem mass spectrometry without any other purification procedures after being filtered with a 0.22 μm organic phase filter. The matrix interferences were effectively removed and recoveries of most pesticides were in the range of 72–121%. Especially, for chlorothalonil, the analysis efficiency of this method was much more favorable than that of the general method, in which dispersive solid‐phase extraction was used as an additional purified procedure. In addition, the limits of quantitation of this method were from 1 to 50 μg/kg. Therefore, a rapid, cost‐effective, labor‐saving method was proposed in the present work, which was suitable for the analysis of 41 pesticide residues in tobacco. 相似文献
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Extracolumn band broadening in multidimensional systems utilizing flow switching is clearly undesirable. In certain cases, i.e. capillary recycle gas chromatography, the success of an experiment is contingent on the minimization of pre- and post-column dispersion of the peaks. Knowledge of these sources of peak distortion is necessary to optimize the experimental design. A system that extracts statistical parameters from real chromatographic peaks is discussed and used to evaluate band broadening in a capillary recycle experiment. 相似文献
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衍生-气相色谱法测定水产品中的游离甲醛 总被引:4,自引:0,他引:4
建立了水产品中游离甲醛残留量的衍生-气相色谱快速检测方法,对衍生剂、抗干扰剂、萃取剂、色谱条件进行了研究.用HP-5 (30 m×0.32 mm i.d.,0.25 μm)毛细管色谱柱,程序升温,γ-ECD检测器,外标法定量.甲醛的检出限为0.05 mg/kg,在0.1~20.0 mg/L范围内,其线性相关系数R2=0.9994,标准偏差为0.041,在0.5、 1.5、 5.0 mg/kg 3个添加水平下回收率为89.6%~102.6%.3个实验室间的RSD为2.7%~4.4%. 相似文献
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鱼贝类水产品中有机锡的气相色谱-脉冲火焰光度法测定研究 总被引:2,自引:0,他引:2
采用振荡萃取法,以凝胶渗透色谱净化浓缩液,用戊基溴化镁衍生;衍生物经弗罗里硅土净化后,用气相色谱-脉冲火焰光度法(GC-PFPD)测定,以内标法定量,建立了鱼贝类水产品中8种有机锡的分析方法。方法的线性范围在10-500μg/mL之间,检出限为1.0μg/kg左右。以牡蛎干粉为基质,在10和40μg/kg水平下加标,各有机锡的平均回收率在82.0%-104%之间,相对标准差(RSD)为1.4%-13.3%,牡蛎标准参考物测定结果落在定值范围内。 相似文献